Very annoying issue using the trixie os release on the pi5

[Bill E]

A user is running t30dpy3. He can slide it over the taskbar. It turns out this is an explicitly defined behavior in wayland using the labwc compositor, which is the release default. Grrr. This is done at the OS level, SDL3 has no direct control. Same thing with SDL2 and p2simES. There are some fairly complex coding hacks I can try, but not sure it's worth it.

I've had nothing but problems with Wayland and labwc on other boxes with other apps that aren't mine. It is definitely not ready for prime time. Oh, and the prior release, bookworm, didn't have any of these problems. Trixie messes up vnc also for multiple monitors.

Bill

[Bill E]

I should have elaborated a bit. This is far more serious than you might think. Since an app's window is not constrained, if the window is bigger than your screen size, it just covers everything, including the taskbar. Plus, the window's title bar is also off the screen, you are just screwed. Nothing to drag, no way to get to the task bar, etc. With X11, the title bar was blocked from going off the top so you could then drag it around. I really feel like ranting about devs and 'architects' that fix things with no understanding of the side effects or how it will affect all the users.

Bill

[Bradford Miller]

Never attribute to stupidity what can be adequately explained by malice.

On Jun 9, 2026, at 8:54 PM, Bill E <wjegr...@gmail.com> wrote:

I should have elaborated a bit. This is far more serious than you might think. Since an app's window is not constrained, if the window is bigger than your screen size, it just covers everything, including the taskbar. Plus, the window's title bar is also off the screen, you are just screwed. Nothing to drag, no way to get to the task bar, etc. With X11, the title bar was blocked from going off the top so you could then drag it around. I really feel like ranting about devs and 'architects' that fix things with no understanding of the side effects or how it will affect all the users.

Bill

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[Whit Turner]

Would switching back to X11 in raspi-config help with this?

Whit

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[Bill E]

Yes, but I don't want to force people to do that. I have after discussions with Claude (yes, the 'AI') and with Carlo V who has been incredibly helpful I've decided to put in a code hack. Both t30dpy and t30dpy3 check to see if wayland is being used and if so check the physical window size and if it is smaller than the startup size minus a protective margin they resize to that size. The protective margin is because an app can't query for anything useful or important like the task bar dimensions, so a fixed 128 pixels is used. Wayland and labwc also don't allow an app to specify where the window is to be opened(!), they decide. Why? It was considered a 'security issue' if allowed. Really? Insane.

Also noting again that p7sim suffers from the same issue. My modded version of that allows a size setting to be given on the command line so that can be used.

There is no reliable fix for an app window being able to slide over the taskbar, that is a labwc issue. That can be avoided by using a different desktop compositor like Gnome.

Just to be clear, this is also a problem only if your physical display is smaller than whatever size you start the app with.

Anyway, I'll check the changes in later today after more testing. Also note that vncs tend to perform poorly if there are rapidly updating images, like snowflake in t30 or in p7sim. This is specific to the pi5 running wayland and has to do with a lame implementation talking to the gpu.

All in all, Raspberry should at least be embarrassed. None of this is an issue on any pi other than the pi5, but you don't get the faster graphics gpu except on the 5.

Bill

[Carlo Valpiani]

Hi Bill,

A feature request for those of us who want to live dangerously with window managers.

Would it be possible to add a flag for t30dpy3 such that the "protective margin" is not applied? 

If the s=1024 and the flag set on a 1024 pixel high display then the t30dpy window is 1024x1024?

TIA

Carlo

[Bill E]

But of course. I'll add that soon, stay tuned.

Bill

[Bill E]

Per request, t30dpy and t30dpy3 will not apply the wayland/labwc protection if an explicit size has been given on the command line or in the config file.

Bill

[Carlo Valpiani]

Thanks Bill,

Installed it and the mods work fine under X11 but not under Wayland. Still the same behaviour of pruning the window size if the window size is near the panel height. Tried both with config file and command line on Wayland.

Toggling fullscreen using "f" still works a treat. 

Carlo

[Bill E]

I probably missed something, I'll check it out as I put back window centering under x11.

Bill